The present invention is generally directed to a mechanism for transforming an input torque profile to an output torque profile and to actuator assemblies that employ such a mechanism.
Torque motors are employed in a variety of applications, e.g., to open and close exhaust gas recirculation (EGR) valves in automobiles. Such applications typically require a high torque at the beginning of a stroke to initiate movement of a component followed by a lower torque to maintain the movement against resistive forces. Conventional torque motors typically do not allow tailoring their torque profile to a particular application. For example, they can provide a substantially uniform torque over the entire range of a stroke, which can result in the torque motor providing a higher torque than needed over a large portion of the stroke. In other words, the torque motor would provide a torque corresponding to the peak torque demand even when a lower torque is needed. This can, in turn, lead to inefficient use of energy as well as a bigger size for the torque motor.
Accordingly, there is a need for mechanisms that allow tailoring a torque profile of a torque motor to a particular application.